Apparatus for use in teaching and training aviators



E. ST. JOHN Feb. 13, 1945.

APPARATUS FOR USE IN TEACHING AND TRAINING AVIATORS Filed April 24, 1943 5 Sheets-Sheet 1 E $1. TOHN INVENTofC a d ATTII,

Feb. 13, 1945. JOHN 2,369,418

APPARATUS FOR USE IN TEACHING AND TRAINING AVIATORS Filed April 24, 1943 5 Sheets-Sheet 2 YYQD Elam 'r.To H N lNvENToR Qua ATT' E. sT. JOHN 2,369,418

APPARATUS FOR USE IN TEACHING AND TRAINING AVIATORS Feb 13', 1945.

Filed April 24, 1943 5 Sheets-Sheet 3 EZIC, ST Tow N INVENTOQ WW Q ATTY.

Feb. 13, 1945. E. ST. JOHN 2,369,418

APPARATUS FOR USE IN TEACHING AND TRAINING AVIATORS Filed April 24, 1943 SSheets-Sheet 4 I I I 54 5L? ERIC. ST Ten-1N \NvEN'ro E,

Feb. 13, 1945. E 51 N 2,369,418

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INVENTOfi.

teaching and training aviators or as an amuse complete instructional or operational. flight from ment device. j h taking-on, climbing to a highaltitude, executing, Two fundamental objects which are the con-'- manoeuvres, andlanding, thus permittingawider control and operation of a simple aircraftun- A further object of the present invention is der normal conditions are (i) the assimilation to provide means whereby progressive instrucv extent with those which are obtained in the purpos of extending the scope thereof, means case of an actual aircraft infli-ght. The dummy, whereby the normal operation of the apparatus fuselage is fitted with the .usual control surfaces and/or'its response to movement of the controls arcuatfi Screen, r pon its interior surratus, for use in teaching and training aviators,

altitudes.

it can ofier little or noassistance to the pupil pictures d'epictingviews as would be seen by the in practising taking-ofi andlandin W pilot 'ofa real aircraft. l l

Above a predetermined distance from the 'The cinematographic projector is so constructground, the apparent forward: speed or an aired that its film feed mechanism may be operaprouide an; apparatus which: simulates morerealis manner as torepresent such visual changes as tically the appearance of a natural. horizon and would be seen by thepi-Iot of a real aircraft.

Patented Feb. 13,1 945 h h UNITED STATES PA OFFICE 1 fr a APPARATUS FOR USE IN TEACHING AND- l v TRAINING AVIATORS h Eric St. Jenn, Cardilr' Wales Application April 24, 1943, Serial No. 484,337

In Great Britain April 24, 1941 v t l l 'I'Glainhs. .(Cl. --12) h t I This invention relatesto apparatus for use in pilot of an'aircraft throughout all phases of a I cern of a pupil undergoing instruction in the 5 range of ground instruction.

by the pupil of a sound knowledge of the Worktional exercises, with attendant oral explanations, ing and effect of the various control 'provided maybe presented to the pupil under training, and (ii) the use of the earths natural horizon without the assistance of an instructor, and to as azguide to-the attitude anddirection of the increase the realism obtainedby providing means aircraft under control. l i v whereby correct engine sounds in relation to Vari At the present time it is usual when trainous settings of thethrottle control may be heard me aviators in the elementaryphases of flying, bythe pupil. 1 V to provide a dummy fuselage which is mounted 1 A further object of the invention is to proon a support in such a way as to enable it to be vide, in association with the automatic instrucmoved into positions corresponding to a large 7 tional exercises already referredto and for the and contains a cockpit in which the pupil is may be influencedin such a Way as tosimulafi seated A set of normal aeroplane controls is the changed behaviour and/or response to con provided in the cockpit and when operated by trols that areal aircraft would have when oper the pupil cause the dummy fuselage to assume, ated under predetermined changed conditions, within predetermined limitsattitudes correspond- 25 such asfly g in rough i in v i aing to those which a normalaircraft assumes tions of wind strength and direction, and during when its controls are operated in a similar flight without engine power (for usein forced manner; l w landing practice).

At a suitable distance from thefuselage is an According to the present invention an appaface" a printed or painted representation of a l or as an amusement device, and includin a landscape and natural horizon as would be seen, dummy fuselage with a cockpit for aocommodat by the pilot of an aeroplane flying at certainifixed ing a pupil or other person; the fuselage bein 9 l i provided with a set of normal controls, and being This arrangement, although satisfactorywith capable of being tilted or turned, isprovided regard to instruction'and practice in the first with a cinematographic projector mounted .in the of the two main objects above referred toQhas a fuselage for projecting a scenic picture on a very limited use with regard to the second obscreen mounted in such a position inthe fuselage ject. Duri-ngtheoperation of an aircraft withas to; be visible to theoccupant of the cockpit m a predetermined distance from the ground, 40 in all. positions of the fuselage, the projector i. e; during the important manoeuvres of takingbeing mounted in the fuselagein such a manner ofiand. landing, a: primefconsid'eration is the for"- that the scenery projected on to th screenalwarct speed of. the aircraft, and as theqexisting ways has'its horizon apparently fixed in space training: system described has no method of repirrespective of the position of the aircraft. resenting a visual indication of forward motion, On t e-the screen are projectedcinematographic craft relative tothe earth issmall and is; for tiv'ely associated with the controls inthe cockthe purpose of such ground training, ignored. pit, so that as the controls are operated, the It is: a-main obaect of. the present invention to scenery visibleon the screen is influenced in a landscape. su y s d be een y the N5 1 The scenery may depict the correctview's as issued Sept. 29,

rangement movement of the fuselage inthefroll would be seen during all phases of a flight and in correct sequence and various films may be used in order to obtain such widely varying operational condition as flare path landings by night, operations conducted from the sea or from a marine aircraft carrier.

Oral explanations associated with variousmanoeuvres may be heard through headphones worn by the occupant of the cockpit and are derived from a sound track of an instructors voice recorded "on the cinematographic film. Engine sounds derived from optically recorded sound tracks are recorded on a separate drum in the form of progressive engine sound tracks, means being provided whereby movement of a dummy throttle control lever in the cockpit causes the appropriate. sound track to be selected and'heard by the pupil through headphones.

A series of control tracks optically recorded on the cinematographic film provide means wherebly electromagnetic switches are operated, so as to produce additional movements simulating extraneous influences on the fuselage.

The invention will now be described by way of example with reference to the accompanying drawings, wherein:

Fig. '1 is a side elevation, partly in section, of a dummy fuselage mounted on a support,

Fig. la shows an elevation of a projection screen,

Fig. 2 shows a plan view, partly in section, of a projector,

Fig. 3 is a side view of Fig. 2,

Fig. 3a shows sun and planet mechanism to a larger scale.

Fig. 4 is a partial View looking on the right hand end of Fig. 3, r

Fig. 5 shows an elevation, partly in section, of an arrangement for controlling the speed of the projection motor and the arrangement for drivingand adjusting a drum on which engine sounds have been recorded optically, and

Fig. 6 shows a film and a scanning device through which the film passes.

Referring first to Fig. 1 a dummy fuselage 6 is provided with ailerons 5, a rudder 9, elevators 8 and with a cockpit 26 containing the usual controls, which are not shown.

The fuselage 6-is mounted on a vertical supporting shaft or spindle I5, between the top of which and the fuselage is located a universal joint I0 which provides for a predetermined amount of movement of the fuselage 6 in looping and rolling planes. The vertical shaft I5 is mounted in anti-friction bearings I4, supported by a fixed base I3, so as to allow the vertical shaft I5 and thus the fuselage 6 free rotation in the yawing plane.

- Movement of the fuselage, under the action of the controls, may be effected by hydraulic pressure, electric motors and gearing, or.by the variation of air pressure in a number of supporting bellows mounted between the fuselage 6 and a base plate I I, with an upstanding rim, keyed to the shaft I5. The bellows arrangementis for example as described in U. S. Patent No. 1,825,462

1931. With a bellows ar- Movement of the fuselage in -,the looping I5 and pulleys l5', l5". trolled from the cockpit 26.

plane is effected by operating air valves connected to an appropriate control in the cockpit 26 so as to vary the air pressure in two bellows I9, I2 located underneath the fuselage 6 along the longitudinal centre line of the fuselage 6, the bellows I9 being in front of the shaft I5 and the bellows I2 behind the shaft I5. The bellows I9,

I2 are supported by the plate II and enclosed in a flexible casing 2I.

Movement of the fuselage in the yawing plane, i. e. turning, is effected by means of a vacuum operated motor I5 which drives the shaft I5 through suitable gearing such as a belt This motor is con- The various movements of the fuselage may be effected independently of one another or simultaneously.

A projection screen 23 is mounted in any suitable manner at the forward end of the nose of the fuselage 6. In the case of a biplane as shown the screen 23 is secured to the leading edges of top and bottom main planes 2, 22 and to the leading edges of a pair of front interplane struts 3 located in suitable spaced relation on opposite sides of the nose of the fuselage 6.

A cinematograph projector I is mounted in a suitable position inside the fuselage 6 so that the beam therefrom passes forwardly along the inside of the fuselage 6 and out through the open front of the nose of the fuselage B, where the screen 23 is provided with a cut-away portion 25 (Fig. la) whichfits around the nose tip. In order toobtain a long throw between the projector I and the screen 23, a reflecting surface 24 is carried in a suitable frame work I, extending forwardly from the fuselage 6, this reflecting surface 24 being set at a suitable angle so that it reflects the beam from the projector I on to the rear of the screen 23.

The screen 23 is constructed of a suitable translucent material and, as will be seen in Fig. 1, is so positioned that images projected thereon can be viewed by the occupant of a seat 2! in the cockpit 25.

As shown in Fig. 2 the projector I is. in many respects, of similar construction to a normal cinematographic projector. It is provided with a film feed spool 3|, a feed sprocket 38, a film gate 42 through which a film 34 is passed between a light source 31, which is located betweena reflector 3B, and a condenser lens 40, and a projection lens system 41. The film gate 42 is provided with front and back metal plates each provided'with an oblong hole forming the gate mask aperture. l

to produce intermittent movement'of the film 34 which, after leaving the beater 5|, passes around a guide roller 52, then around a first take-up sprocket wheel 50. The film 34 then passes around a sprocket wheel 54 from which it passes around a guide roller 56, through a second film gate 5'! of a sound and control track scanning system 55.

When the film 34 leaves the system 55 it passes around a guide ,roller 60, to a final take up sprocket 6| and onto a take-up spool 62.

A suitable rotary intermittent shutter is provided but this is. not shown in Fig. 2 for the sake of clearness.

The projector I with its base plate 35 is mounted in the horizontal position so that the film 34 passes through the gate 42 horizontally instead of vertically as in the case of normal projectors.

ageebwrs comers oft'hi's plate l8 are-shaped so as toislide Yin V-groovesformed inguide blocks 39 "5 la and 53*- secured to: themain base plate: 35;

vertical shafta-flll lpassing through and free to rotate in the rnai n base plate 35 isprovided atits;upper end with a screwthread 8-3 engaging pulley 80 and a-b'elt Bil" drives apull'ewat keyed heater 5 L From the shaft: 84 the drive is transmitted through the gear wheels. 84a, sau to a shaft 89c; which through sun'- and' planetgearingv the sprocket wheel 50. The shaft Silt drives l through'bevel. wheels 912a a; main shaft 139Whf0h through] bevel wheels; ltai drives a: vertical: shaft onzlwzhlch; the sprocket wheel; M2 is; keyed. and a horlzontalshatt 1w which}. through bevelwheeIs;

dtlves a vertical shaft. om which the sprocket wheel 38 is keyedl The; shaft.- l9r alsa drives,

through. bevel: wheels-19rd,. a verticzal shaft; to

, 91,196 so; seaweeds-11amsncnecny driving:

the:sprooket=wheel 8t is; keyed; A. flexible extension. 19c: drives the take Flip; spool" 62; through;

manner reductionwgear 'lilf.

As the screen 23 is attached tothe fuselage-5 and consequently moves "therewith a; scene pro-" jectedib'y aifixedi projector: 1 wouldremain inla iixedposi-tion on the screen 23. This would be unsuitable for the: purpose of thepresent. inven:

tion as, theprojected fhorizon must; nottilt= or,

alter? its: apparent position in space; whatever attitude the fuselage B may assume. It isjthereforenecessary tomount thepr-ojector Mn. the

fuselage B- in such a manner that thMhorizoni remains: stationary no matter what tilted position is assumed by the fuselage 6.

with a corresponding thread in the'separate: plate cured? a-piniorr W rotating freely on a spindle a extending laterally .fronr a bracket H forming theupperpart of the universal joint HI on which. the fuselage Eris mounted. The. pinion Til gears with laiixed gear wheel- 12* mounted on. a bracket 65 attached to the intermediate circular memher 8 6 of" the universal joint l ll. During movementoftheiuselage 6 in the-Iooping plane, i. e. about a centre coinciding with the; axis of the ti'onary whilst thefpinioni 1 0 runs thereon thus rotatihgthe flexible shaft 85 and consequently.

also the shaft 90 so that the plate 45 is raised or' loweredi by reason of screw thread 83 (Fig: 3): turning thereim i 1 Thevpitch of the teeth of the wheels 10', T2 is n so chosen that the ra-i'sihgand lowering of the f plate is-i'n the correct relation to the angle of tiltingofbthe fuselage about the axisof the v hearings 69. a r

In ord'erthat the filin- 34 may notice damaged during this movement'loops are provided in the mm 3% betweenthe sprocket 38' and the gate 42 and between the-sprockets and 54 Tmallow the plate 45 tabe raised and lowered shaftst i 89'- with tubularportionsare fitted on Inorder to obtain this result the projector 1 iswpivotally mounted at-opposite ends of its long i tudinalaaxis inibearings 46f, 32 in; aitrames 18.- secured to: a suitable support 18a, provided. forthe purpose in the fuselage 6. 1

n The front bearing 46 houses a tube: 4.8 in; which thelens-System14! is mounted and to which is attached a frontupward extension-J 8.1 in the base plate 35.

The rear bearing32 houses a beit 33japroject ingfrom a bracket33 secured to the base plate 3F. arm T4 extending. laterally fiomthje .front extension 81 ofthebaseplate iscon'nected by aswi'veli coupling 15"to a link I'Gofwhichlthe lower end is connected by a swivel coupling '53 to an arm 64 rigidly attached to the shaft [5.

When the fuselage 6 moves in the rolling plane the projector 1 is also displaced about a centre coinciding with the axis of the pintle bearings 68 of the universal joint [0 but is retained in the horizontal position by'the link T6. The swivel couplings 15-63, which connect the upper and x lower ends of the link 18 to the arms 14, 64', how;- ever, allow unrestricted; movement of the projector 1 about a centre coinciding" with theaxis moves' in the looping plane.

When the fuselage a is movedin the sl e ing"; plane*-,i.e. raises orlowers it'snose; the projector "land screen 23 movingin the same plane would normally cause the projected horizon to rise or fall with respect to the earth. i

To counteract this some of the parts of the projector 1 are mounted on a separatefplate in order that aproportionate vertical movement may be imparted thereto.

.of the pintle bearings 69" when the fuselage 6 For this'purpose the filni gate 42, the heater 5 I, the guide roller 52 and the taker-up sprocket 5'0 are mounted on the separate plate 45. The four the upper ends ofthe shafts; 91 towhichthey are secured by pin and slotconnections 82', 88.

When the fuselage'fi moves in the "yawing piano, e: swings its nose to the right or left, H

any fixed pointin the projectedhorizon must remain stationary relatively tothe earth. For

this purpose the gear ratio of the drive common to the sproclfrets 38'; 50; 54 G1 is varied as hereifnatter described whilst the drive ofthe beater 5 is drivenat a constant speed. As above described the beater 51- is driven from the shaft 8t, whilst the sprockets are driven through the sun and plane't' gearing; For" varyingth'e gear ratio ofthe drive to the sprockets 38, 50*, 54, 61

a drive is transmitted from the shaft 89a (Fig. 3a) tothe planet wheels 96, 99 through the sun wheel 91 The" planet wheels 96*, 99 drive the ii'ange 98-, whilst-a cross arm '95, on which the planet wheels 967, Ware mounted, remains sta tionary when the fuselage is in the normal positiorr and the gearratio-is thus"constant. When yawingmovementoccurs, the cross arm is causedto rotate; and the planet wheels 96, 99 move around the eriphery of the sun wheel .91 so that: the velocity ratio ofthe sprockets is increased or reduced according to the direction of rotation of the: cross arm 95. Thus while the beater 51-, of which the speed-50f rotation remains constant, causes: the iii-m 34 to be moved through i the gate 52 at constant intervalsand then to remain stationary whilst the picture is projected, any increase or decrease! in thejspeedi of rotation of the sprockets causes a. greater or shorter" portion: oi the mm to be fed bythe beater, theresult ct which is: to: produce on the: screen a lateral. l

movementof the picture to' left or right;

The cross arm 95-, which is freely rotated about the shaft 89a, is secured to a toothed wheel I 00,

also freely rotatableabouttheshaft 8921: and gearing with a toothed wheel 94 secured to'a flexible shaft 93. Y

The lower end of the fleXible shaft'93 is secured to a spindle I8 (Fig.1) passing freely through the plate II and provided .at its lower end with a pinion I1 gearing with'a sun wheel I3 secured to the non-rotatable support I3. 1

In order to control'the apparent flying speed of the aircraft relatively to the projected scenery the driving speed of the motor 801s variedby controlling an electrical resistance arranged in,

sothat movement of the control lever .I lresults in a proportionate movement of the arm I I6 sliding 1 over. contact studs II1 of a resistance located in a box NM. The effective range of the resistance is such that its maximum value corre: sponds with the closed portion of an engine throttle, whilst its minimum value corresponds with a fully open throttle In order to obtain sounds corresponding with various settings of the dummy throttle lever H5 there is provided a drum consisting of an end plate I05 to Which'issecured a transparent cylinder I04provided on its outer surface with a series of optically recorded sound tracks I03.

The separate sound tracks I03 are endless and each represents the sound of an aero engine run ning at aparticular speed. The tracks I03 are arrangedside by side in progressive order so as to cover substantially a completerange of sounds at different engine speeds.

.An exciter lamp I23 is mounted in a housing I24 located below the cylinder I04. Opposite the lamp I23 the housing I24 is provided with a condenser lens system I at the outer end of which is a cover plate I22 provided with a scanning slot. This slot is of a width equal to an individual sound track I03 so that the rays from the lamp I23 only traverse the sound track'I03 which is in register with the slot at any particular moment. The rays from the lamp I23 impinge upon a photo-electric cell I02, located inside the cylinder I04 through a lens system I21, the cell I02 being shielded by a housing I26 secured to a fixed support I28. I

In order to select the appropriate sound track I03, corresponding to a particular position of the lever I I5 the drum I04, I05 is mounted on a shaft I06, which is rotatably mounted in supports I28, I 2| II 8 and of which one end is connected by a swivel joint III to a link I12. This'link H2 is connected by a hinge pin II3 to the link I I4 and lever H6. 3

When the lever H5 is actuated to control the resistance lever IIB it thus also moves the shaft I06 longitudinally in the supports I28, I 2|, H8; This longitudinal movement of the shaft I 06 is limited by a slot I I 0, in a sleeve I08 fittedaround the shaft I06 between the supports I2I, H9, with which engages a pin! 09 secured to the shaft I06.

For the purpose of rotating the cylinder I04 there is provided a synchronous electric motor II9 which drives the cylinder I04 through suitable reduction which as shown in Figure 5 consists of a pinion I20 keyed to the motor shaft. gearing with a toothed wheel I01 keyed to the sleeve I08.

1The photo-electric, cell I02 is connected by suitable amplifier I02 .to earphones-worn by a pupil or other occupant of'theseat 21 in the cockpit 26. 1 I

As shown in Figure 6 the film 34 is provided with perforations I30, similar to an ordinary cinematographic film. The images, as above described, are arranged side by side and are photographed by means of a Wide angle lens-so'that when projected each frame I34 covers substan-;-

tially a larger field of view than the area I necessary for fitting the projection screen. 23. As a result the screen 23 is always'covered with a complete picture irrespective of the position of e the fuselage 6. I

" Between the images I34 and one row of perforations I30 is provided an optically recorded sound track I 33 similar to thaton a normalsound film. Atthe edge of the film 34 beyond the per The track I33 carries recorded instructions or explanations given by an instructor. As will be appreciated these recordings are only practical when the film" 34 passes through the gate 51 of a the scanning device 55 at a constant speed. When the film 34 passes through the scanning device 55 the sound and control tracks I33, I3I,. I32 are scanned by light rays from a series of exciter lamps I36, I31, I313. The rays pass through condenser systems I39 and through the tracks-I33, I 3I,'I32, opposite which are located slits I40 'cut inthe gate 51. After leaving the tracks the rays pass through collector lens systems MI and impinge upon photo-electric cells I42, I43, I44.

The photo electric cell I42 is connected through a suitable amplifier-to the earphones worn by the pupil or otherperson in the cockpit 26.

By theoperation of these valves mechanicaleffects can be introduced upon the operation of the apparatus in order to simulate actual flying or operating conditions as occur due to wind and other forces. 7

A stereoscopic film may be used so as to obtain greater realism of flying. In such a case the occupant is provided with a suitable viewing device. v v The scenery projected on to the screen is preferably previously photographed from an aircraft in flight. The images'may be arranged one above the other on the projector film as on usual films, in which case the projector is arranged vertically. For the reasons'stated above it ishowever preferred toarrange the images side by side and to use the projector in a horizontal position.

Instead of the beater type of feed mechanism, there may be used -'a maltese cross device, a claw mechanism or other well known intermittent feed device for the film. I I

The film is preferably of the 35 mm. type,

whilst the field of the lens system 41 is preferably such as to extend over only a portion of A pupil or other person when seated in the tofollow in the apparatus. The pupil ascends ccckpit'it Tfits son the headphones and :closes a niamswitchwhere'by thetmiotors 8.0 and 1 I9 rare setin .toperatiocn. ilhe projector 11' projects on: to the screen 23 a suitable picture such as a pic tureofwa flying groundzas would be seen from the .cockpitofa stationary aircraft. The pupil may-then be instructed to go through the normal starting procedurein response to .oral instructionsxsuch asgiveniby an instructor. The pupil hears the engine running and is readyto take off. Thedirecton of the wind maybe seen from a wind direction indicator located ata .distance. During flight the pupil receives the :recorded instructions through the earphones as thoughi in radio: communication :with fan instructor :in .a l

separate plane 'whichmay appear onthescreen. WJQIITFH'IB screen theinstructors plane will for example appear-to take-on, climb, execute any manoeuvres :w-ithin the mechanical scope of the apparatus, approach anaerodrome and land, these :being operations which the pupil is" required will naturally lag behind afewEseconds.

.As an example of the operation oftthe special bias efiectsgshouldthe pupil notice beforetaking- I ofithat the Wind -di1iectionwas indicated as being across thisyfiight path, he will realize that it will be necessary to counteract the resulting influence on his machine. For example, one effect of taking-off across windis that owingto the effectof the wind on the keel surface, the nose of an aeroplane tends to turninto wind during take-off and thus the pilotis required to operate the rudder to offset this effect. An appropriate transparent portion of a control track having permittedthe exciter lamps rays to'actuate the relevant photoelectric cell, theappropriate air suction valve is base plate consisting of two. parts, xonevlofsai-d parts being wcapable of :being raised and lowered plate on "which said projector is mounted, said relatively 'to the other, said proj ector including a light j source, a reflector, a. condenser lens, a film gate, a projection lens system, e, feed sprocket, a

beater, a guide roller a first take-up sprocket and a second take-up sprocket, the film gate, the beater, thegulde roller and the first take-up sprocket being mounted on the movable part of said base, and the light source, reflectolg'con' denser lens, feed sprocket, the projector lens system andsecond =take up sprocket'being mount- 8 ed on the other part of said baseplate, said movable partofsaid base having a screw threaded yholetherein, a :vertical shaft having a screw threaded portionjat the upper'endthereof, said screw threaded portion engaging said screw threaded hole, a flexible shaft connected to the lower end of saidscrew threaded shaft, a pinion secured to thefree end -of said shaft connected to said universal joint; said fixed gear wheel being "engaged by said pinion, the arrangement serving caused to operate as previously described and the trainer commences to turn. In order to keep his aeroplane heading in the right direction for takeoff the pupil must apply the opposite rudder and thus balance the ap arent effect of the cross wind.

It can be seen that this device may be used to obtain many different combinations of bias ffects in conjunction with suitable flight sequences and may'also be used ;to influence the mechanical operation of the apparatus in order to simulate various types of aircraft. l

The invention is readily adaptable to any type of aircraft and may be built on a larger scale if desired in order to accommodate a pupil an instructor with interconnected controls.

Iclaim: c l l 1. In an apparatus for the purpose described 1 the combination comprising a fixed base, a vertical shaft rotatably mounted in said base, a dummy fuselage mounted on said vertical shaft, a universal joint between said vertical shaft and said fuselage,jmeans forproducing movements of said fuselage in looping, rolling. and yawing planes, a cinematographic projector pivotally mounted in said fuselage about an axis parallel to the longitudinal axis of said fuselage, and linkage between said projector and said vertical shaft, said linkage serving to maintain said projector in a substantially horizontal position irrespective of any lateral tilting of the said fuselage. 2. Inapparatus according to claim 1, a base.

plate on which said projector is mounted, said linkage including an arm extending laterally from said base plate, an arm attached rigidly to said vertical shaft, a link extending betweensaid arms, and a pair of swivelling couplings connect.- ing the opposite'ends of said link to said arms.

3. In apparatus according to claim 1, a base to raise or lower themovable part of said base 1 according to the verticalmovementof the nose.

of the fuselagewhen the latter moves in a.1ooping plane. 3 l

4. In apparatus according to claim 1, a base plate on which said projector is mounted, said base plate consisting of two parts, one of said parts being capable of being raised andlowered relatively to the other, said projector including a 1 light source, areflector, a condenser lens, a film gate, a projection lens system, a feedsprocket, a

beater, a guide roller, a first take-up sprocket, l

and a second take-up sprocket, the film gate, the

beater, the guide. roller and the first take-up sprocket being mounted on the movable part of said base, and the light source, reflector, condenser lens, feed sprocket, the projector lens system, and second take-up sprocket being mountedon the other part of said base plate,

guide blocks on said other part, said guide blocks 1 each having a V -groove.therein, said movable part having the corners thereof shaped so as to slide in said V-grooves, said movable part of said base having a screw threaded hole therein, a vertical shaft having a screw threaded portion at the upper end thereof, said screw threaded portion engaging said screw threaded hole, a flexible shaft connected to the lower end of said screw threaded shaft, a pinion secured to the free end of saidshaft, and a fixed gear wheel connected to said universal joint, said fixed gear wheel being engaged by saidpinion, the arrangement serving l to raise or lower the movable part of said base according to the vertical movement of the nose of the fuselage when the latter moves in a looping plane.

5. In apparatus according to claim 1, a base plate on which said projector is mounted, said projector including a, light source, a reflector, a

condenser lens, a film gate, a projection lens system, a feed sprocket, a beater, a guideroller,

a first take-up sprocket and a second take-up sprocket, means for driving said beater at a constant speed, driving mechanismefor said sprockets, and means for varying the speed of move ment of said sprocketsrelatively to the speed of said beater when said fuselage moves in a yawing plane}? saidmean comprising a sun wheel' secured to said fixed, support, a pinion gearing with said sun wheel, a flexible shaft to one end of which said pinion is keyed, a pinionsecured to the other end of said flexible shaft, 9. main driv- I is.

ing; shaft, supplementary-shafts; bevel gearing between said supplementary shaftsandsaid main driving shaft, saidmain driving shaft and some of said supplementary shafts'having said sprockets operatively connected thereto, an internally ingtpla'nefltsaid means for-normally driving said, sprockets'at a constant speed relatively tosaid 1 heater, and mean for varying the speed of said sprockets relatively to the speed of said beater toothed flange keyed to said' main'driving shaft,

an auxiliary shaft co-axial' with said main driving shaft meansfordriving saidauxiliary shaft, a sun wheel keyed auxiliary shaft, gal toothed wheel freely rotatable on saidauxiliary shaft and meshing with the toothed wheelat the other end of said-flexible shaft, a cross arm, secured ,to the toothed wheel freely rotatable on the auxiliaryshaft and. a pairof planet wheels rotatably mounted'on said cros arm, said planet wheels gearing with said sun wheel and said flange.

;6. In apparatus according. tojclaiml, a base plate .011 which said projector is mounted, said projector including alight source, areflector; a condenser lens, a filmgate, a projection lensusysterm, a feed. sprocket, a beater,[a guide roller, a first take-up-sprocket and a second take-up sprocket, means for dr ving said heater at a constant speed, driving mechanism for said sprockets, and means for varying the speed of movement of said, sprockets, relatively to the speed of said beater when said fuselage moves in a yawaccording to the movement of said fuselage in the fyawingfplane, said last mentioned means including differential gearing incorporated in said first mentioned driving means, and a flexible shaft connecting said differential gearing to said fixed support.

. .,7. In apparatus for the purpose described the combination comprising a fixed-support, a vertical shaft rotatably mounted .in said support, a dummy fuselage mounted on said shaft, said fuselagebeing mounted rotatably and universallyupon a vertical axis whereby said fuselage may move, in fro11ing, "looping and yawing planes,,aocinematographic projector mounted in said. fuselage. and capable of rocking abouta horizontal axis parallel to the longitudinal axis of said fuselage, when in the normal position,

and a linkage connectingsaid projector to said vertical shaft, the arrangement being such that a vertical plane passing through the longitudinal axis of the projector is parallel to the" vertical axis of the shaft in all positions of the fuselage.

- ERIC ST. JOHN. 

